AnswerID: 44944 Submitted: Saturday, Jan 31, 2004 at 09:59
Oilburner
replied:
Hi Peter, I'm mechanical engineer and what you are asking about I had as a subject in university. Both systems will give you heaps of power and torque, not only in the dyno figures but in terms of responsiveness and seat of the pants feeling. If you purchase either kit from a serious manufactures they will both be as reliable and will probably outlast your engine. Superchargers have the advantage of giving you that extra power from idle all the way to redline. Normally turbos take a second to build up speed from idle so you have turbo lag, that is the time that passes from the moment you hit the pedal to the moment you start feeling the engine deliver all its potential. Lately that advantage is becoming really slim, with the use of wastegates you can use smaller turbines that have lower inertias and spool up much faster, also some turbos are now coming with ball bearings that have lower friction and also help the turbine gain speed (and consecuently gain boost) in less time. One advantage of turbos over superchargers is the reason why trucks and buses use them. Both the turbo and the supercharger are basically air pumps, the difference lies in where the power to drive those pumps comes from. In the case of a turbo that power comes from exaust gases with energy that would otherwise have been tossed into the atmosphere. In the case of a supercharger that power comes from the flywheel; of course it drains lees power than what is gained by its use but it also means that overall the engine is less efficient. This means that for the same final power output a turbocharged engine is likely to burn less fuel than that same engine with a supercharger. How much more fuel? possibly not enough to make a difference unless you drive as many
miles as a commercial truck. Its also true that greater
top end power gains can be obtained with turbos but in a GQ I don't think you'll care much about that.
Years ago the advantage in terms of low end performance and response of the supercharger was evident, but lately turbo systems have been perfected to imitate the performance of a supercharger with the advantage of being quite less expensive.
If it were my truck I'd install a turbo + intercooler, but in the end it will boil down to costs and how much confidence you have in the manufacturer of either kit.
Hope this helps you in making your choice.
Regards,
Marcos.
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